Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós...
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![Page 1: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/1.jpg)
Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies
Szilveszter Miklós HarangozóZimányi Winter School 2013
Consultant: Dr. Gábor Papp
ELTE – TTKDepartment of Theoretical
Physics
Supervisor:Dr. Gergely Gábor BarnaföldiWigner RCP of the HASDepartment of Particle & Nuclear Physics
![Page 2: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/2.jpg)
pQCD based parton model
• Nucleon-Nucleon reactions
• Factorization: we assume, the process can be factorized into 3 independent phase
![Page 3: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/3.jpg)
pQCD based parton model
• We calculate the cross sections with a convolution described above.
• We characterize the PDFs & FFs as probability density functions, which can not be calculated perturbatively.
Parton Distribution Function (PDF)
hard partonic scattering
Fragmentation Function (FF)
![Page 4: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/4.jpg)
Improving the model
• 40% uncertanity is too much.
• Phenomenological input.
• Parton’s transverse (intrinsic) momenta have been taken into account.
Assume: transverse momentum distribution is Gaussian:
![Page 5: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/5.jpg)
The c.m. energy dependence of
• Comparison of experimental spectra and results of the calculations
• Uncertanities come from the Principle of Minimal Sensitivity
• The model is more sensitive at low pT-s for the parameter
• Take a look at the tendency…
![Page 6: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/6.jpg)
The pT & dependence of
• best fit for every pT value• for a fixed , pT independent
values can be assumed
• best fit for the average pT
• intrinsic transverse momentum seems to decrease
pT dependence of the dependence of the
Good pp reference spectra can be obtained
![Page 7: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/7.jpg)
Proton-Nucleus (pA) collision
• Experience: the yield differs from the expected: atomic number (A) times the one from pp spectra
• Measuring tool: Nuclear Modification Factor (NMF), RpA
• Difference: Nuclear Effects
where is the number of binary collisions
Nuclear Effects
![Page 8: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/8.jpg)
Nuclear Effects
Nuclear Effects
Multiple Scattering
Nuclear Modifications of PDF’s
• Classic and Saturated Glauber model
• Dependence on the impact parameter, b
• Intrinsic transverse momentum distribution broadens:
• Suppression of the yield at low pT-s
• Several parameterizations has been implemented by different groups
![Page 9: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/9.jpg)
Parameters for the saturated Glauber model in pA collisions
Search for the universal Csat constant
Maximum 3-4 collision with CSat ≈ 0.35
![Page 10: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/10.jpg)
Cronin-effect in the saturated Glauber model
Dependency of the Cronin-peak’s maximum against the Atomic number
• ν: number of semihard collisions
• parameters fitted for experiments
• at fixed , peak stays put
![Page 11: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/11.jpg)
Cronin-effect in the saturated Glauber model
Dependency of the Cronin-peak’s maximum against the Atomic number
• shadowing and saturation also suppresses the spectra
• in fully saturated case we get the original dependency
• we can apply a correction to the formula:
![Page 12: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/12.jpg)
The kTpQCD v2.0 code
PDFFFpQCD
![Page 13: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/13.jpg)
The kTpQCD v2.0 code
• Several parameterization can be probed within the same framework
• Original codes has been implemented
• Easy to add new type of PDFs, FFs, etc.
Pro.:
![Page 14: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/14.jpg)
The kTpQCD v2.1 code
eps09s.cpp
Example: New shadowing: EPS09s
Ref.: 10.1007/JHEP07(2012)073
![Page 15: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/15.jpg)
Reconstruction
• HIJING shadowing + Multiple scattering
• EPS09s shadowing
• Both parameterizations gives acceptable results
• For HIJING ν= 4 gives the best fit
• For RHIC results EPS09s is the best
![Page 16: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/16.jpg)
Questions - Motivation
• Which nuclear effects cause the peripheral anomalies?
• Can we model model them?
• To claim a better understand of the Glauber-model
• Find the limits (or a better implementation) of the saturated picture
![Page 17: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/17.jpg)
Summary
• pp reference
• first results on minimum bias collisions
• an updated code with “easy-to-upgrade” properties
We have:
We don’t have: • good enough parameterization for LHC energies
• better understand of the peripheral collisions
• an updated code with “easy-to-upgrade” properties
![Page 18: Nuclear Modifications in Saturated Glauber Model from SPS to LHC Energies Szilveszter Miklós Harangozó Zimányi Winter School 2013 Consultant: Dr. Gábor.](https://reader035.fdocuments.us/reader035/viewer/2022062320/56649d985503460f94a82239/html5/thumbnails/18.jpg)
Thank you for your consideration!